Square tube ,hollow pipe,welded pipe carbon steel rectangular hollow section, good quality, lowest price Square tubeProduct nameSquare tubeSpecificationOD: 15 ... 15mm-400*400mm, WT: 0.6mm-12mmMaterial of Square PipeQ195, Q215, 20#, 10#,StandardsASTM-A53.BS1387-85 ... -2001Zn coating mass200-400g/m2 (glanvaized square pipe)Length of the Gi Square Pipe5.8m-12mProcessing techniqueThreading, coupling, necking ...